The correct option is C kite
The diagonals of a quadrilateral intersect at right angles (Given)
∴ This quadrilateral is a square or a rhombus
But it is also given that this quadrilateral has exactly one axis of symmetry.
So, this quadrilateral cannot be square and rhombus since both square and rhombus have more than one axis of symmetry
Hence, this quadrilateral is a kite.